Introduction

A new version of the Microsoft Windows Update (WU) offline scan file has been released. This new offline scan file is available in addition to the existing WU offline scan file, Wsusscan.cab. The new offline scan file, Wsusscn2.cab, has a new format.

You must update any scanning solution that uses the existing offline scan file by March 2007 so that it uses the new CAB file. Microsoft solutions that use the existing offline scan file include Microsoft Systems Management Server Inventory Tool for Microsoft Updates (SMS ITMU), the Microsoft Baseline Security Analyzer (MBSA), and the Windows Update Agent (WUA).

New releases of SMS ITMU, of the MBSA, and of the WUA stand-alone installer have also been released.

Some non-Microsoft solutions that use the existing WU offline scan file for offline security update detection must also be updated.

The WU offline scan file in the previous format will continue to be updated whenever new security bulletins are released. However, older updates will be removed from each subsequently published version of the Wsusscan.cab file so that the file stays within the size limits.

By March 2007, the existing WU offline scan file will no longer be maintained. At that time, customers will have to use the new Wsusscn2.cab file. Attempts to scan by using Wsusscan.cab will return an error. This error will indicate that the WUA must be upgraded.

More Information

The Wsusscan.cab file has grown with each new security release. Now, the number of files is approaching the maximum that can be included in a single CAB file. Microsoft is upgrading the internal format of the CAB file to resolve this issue.

All products, tools, and solutions that use the Wsusscan.cab file must be updated by March 2007 to use the new offline scan file. The existing CAB file will continue to be updated and published until March 2007. However, Microsoft will reduce the size of the existing CAB file by removing some security update content.

The Wsusscn2.cab file contains metadata from the following classifications: security updates, update rollups, and service packs.

New versions of the following software are available. These new versions use the new Wsusscn2.cab file.

System Management Server Inventory Tool for Microsoft Updates (SMS ITMU) For more information, visit the following Microsoft Web site:

Information for specific customers

If you use Windows Update or Windows Server Update Services but you do not use products that use the Wsusscan.cab file

You do not have to make any changes. The next major release of Windows Update will include the updated CAB file.

If you use SMS ITMU

You must download an updated version of SMS ITMU. This updated version includes an updated Windows Update Agent stand-alone installer. You must deploy the new version of SMS ITMU before March 2007. To download the updated version of SMS ITMU, visit the following Microsoft Web site:

If you use the MBSA 2.0 offline scan feature

You must download an updated version of MBSA and an updated version of the Windows Update stand-alone installer. You must deploy the new versions before March 2007. To download the updated version of MBSA, visit the following Microsoft Web site:

If you use the MBSA 2.0 online scan feature or the MBSA 1.21 online scan feature

If you use MBSA, and you use only the online scan capabilities of MBSA, you do not have to make any changes.

If you use a non-Microsoft solution that uses the Wsusscan.cab file together with the supported WUA public API

You must download the stand-alone installer for the updated WUA on computers that use the supported solution. To download the updated WUA stand-alone installer files, visit the following Microsoft Web sites:

There are no changes to the Windows Update Agent public API because of the CAB file format change.

You must deploy the updates before March 2007.

If you use non-Microsoft solutions that read the Wsusscan.cab file directly

You must obtain updated solution software that can read and process the new CAB file format.

Microsoft does not publish the schema to this file because the internal format is subject to change. We do not recommend solutions that read the CAB file directly. However, Microsoft has provided information about the format changes to any customer or to any solution provider that has an existing solution. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

927745 Detailed information for developers who use the Windows Update offline scan file

For more information, join the WU Offline Scan public forum, or contact Microsoft Product Support Services.

You must deploy these updates by March 2007.

Updates to this article

We will update this article when there is any new information about these releases.

References

For more information about these updates and about other Microsoft security updates, visit the following Microsoft Web site: